Various devices in the marketplace provide a non-energized, continuous emission of a volatile composition (e.g. perfume or insecticide) to the atmosphere, whereby such emission plateaus and tapers off over time. Increasing the emission level of a volatile composition over its emission level in a non-energized state has been attempted with energized air freshening devices that include diffusion assistance means, such as heating elements, piezoelectric elements, and motorized fans. The addition of such diffusion assistance means in a device may require a larger amount of volatile composition, a larger device to accommodate the diffusion assistance means and/or the larger amount of composition, and, in turn, higher manufacturing and product cost. Further, another potential limitation of prior art devices is the wicking substrate which, often times, comprises membranes that limit the diffusion of certain types of volatile materials or comprises a porous substrate that may leak fluid when in certain orientations.
There remains a need for improved devices that emit volatile compositions into the atmosphere.